A service provider is an entity (e.g., a business or an organization) that sells bandwidth provided by a network (e.g., the Internet, a data network, a telecommunication network, etc.) associated with the service provider. Service providers may include telecommunications companies, data carriers, wireless communications providers, Internet service providers, cable television operators offering high-speed Internet access, etc. The rapid growth in the transmission of, for example, video content, audio content, images, and software downloads, is creating much higher bandwidth demands on service providers, with sharp bandwidth peaks that may be due to suddenly popular objects or the occurrence of events.
In order to address such higher bandwidth demands, service providers deploy proxy cache devices, such as, cache servers, in their networks. The cache servers can cache popular objects (e.g., data corresponding to video content, audio content, images, software downloads, etc.), which enables the service providers to optimize network utilization and to save on the backhaul bandwidth costs. In one example, the cache servers may store the objects in storage devices that have a limited number of write operations before failure, referred to as limited usage storage devices herein. Examples of such limited use storage devices include storage devices based on NAND flash technology.
In limited usage storage devices, each storage unit or page has a limited number of erase/write cycles before the page can no longer retain data reliably. Erase/write cycles are required when content of a physical page must change or update, such as when new content needs to be written to the page. In order to guarantee the lifetime (e.g., three years, five years, etc.) of a limited usage storage device, the limited usage storage device must perform some type of erase/write cycle throttling. For example, the storage device may utilize the erase limitations to lengthen write operation times, which may ensure that device usage remains under a particular number of erase/write operations for a given period of time. However, lengthening write operations times may degrade the performance of the storage device. Wear leveling is an industry standard technique used to lengthen the lifetime of a limited usage storage device, but wear leveling fails to provide lifetime guarantees. Wear leveling changes the mapping of logical storage addresses to physical storage addresses over time, so that repeated writes to the same storage address will not wear out a specific part of the storage device.